'The Voice' rewind: See Gaga's duet with Christina Aguilera

It isn't easy to steal the spotlight from "The Voice's" powerhouse Tessanne Chin, but a duet from Lady Gaga and Christina Aguilera will do the trick.

The two superstars teamed up for a performance of Gaga's "Do What U Want," making us think the Mother Monster should've invited XTina onto the single from the start.

[youtube=http://www.youtube.com/watch?v=zoxS2o4H7l0&w=450&h=315]

We just wish that Christina had matched Gaga shoulder-pad for epic shoulder-pad.

And even though "The Voice's" ratings have been disappointing - Tuesday night's episode paled in comparison to last season's final run - at least Celine Dion and Ne-Yo brought their A-game, too.

The singers took the stage during Tuesday night's show to perform their new single, "Incredible." With a title like that, their set is pretty self-explanatory:

[youtube=http://www.youtube.com/watch?v=O1R22SuE55M&w=450&h=315]

The sixth season of "The Voice" is set to bow on February 24 with Usher and Shakira returning in place of Christina Aguilera and CeeLo Green.